Washing machine is a machine that can wash clean the clothes by chemical decomposition and mechanical impact function. It mainly uses driving device to drive impeller to rotate for agitating water and clothes, thereby achieving the function of washing clothes clean. The conventional driving device as power source is motor, the output shaft of motor transfers the torque from motor rotation to the reduction device. It connects the output shaft of reduction device to impeller, thereby achieving to make impeller to rotate.
As the speed of normal motor is quite high, in order to have suitable output speed, the speed of motor needs to be slow down in actual application. Now the normal method is to reduce the speed of motor by the level one pulley of the reducer. In reducer, it can setup one level or more levels gear reduction mechanism to achieve the reduction in certain ratio. This structure is not only complicated, but also occupied large space. To address the above technical issue, some current applied solution is to remove pulley and connect the motor and reducer directly, but due to that the motor itself and the reducer still in individual position, so they occupies mounting space separately. Therefore, the structure is not compact enough, and the volume is quite large.
To address the abovementioned technical issue, one type of external rotor motor assembly is provided according to the disclosed No. CN102142734A of China invention, which includes motor body, driving shaft, and transmission device. The driving shaft is fixed on the transmission device, motor itself directly drives the driving shaft, the motor body has inner diameter space, and the transmission device is mounted within the inner diameter space. Although the structure has already reduced the occupied space in certain extent, its principle is to use the inner circumference space of the stator of the outer rotor motor for mounting the transmission device to the inner diameter space of stator by mounting parts. So it cannot be applied to the inner rotor motor without the inner space, so it has certain limitation. Meanwhile, its motor itself directly drives the driving shaft, and then to reduce the speed of driving shaft by the transmission device mounting within the inner diameter space of motor. so it only reduces the occupied space in certain extent, but the structure is not compact enough. Further, when the transmission device needs to achieve higher gear ratio and needs to increase the volume, it certainly needs to make the inner diameter of the outer rotor motor to increase the volume to realize this application. Therefore, it obviously does not solve the real technical problem.
In addition, the current washing machines all carry out washing in a certain fixed speed, no matter the washing load is big or small, the wash shaft still rotates at the same speed to wash, this kind of washing method not only can easily damage the washing clothes, but also it can damage the motor of washing machine if overloaded.